Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Equine Health
Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Correct occlusive bladder width for indirect blood pressure measurement in horses. The influence of occlusive bladder width on blood pressure, measured indirectly using a doppler ultrasound technique at the middle coccygeal artery, was studied in 6 anesthetized horses. The relationship was investigated on tails with and without hair, and the optimum bladder width (BW)/tail girth (TG) ratio was determined for systolic pressure (SP) and diastolic pressure (DP), with the data grouped as unclipped tails (TT-1), clipped tails (TT-2), and both unclipped and clipped tails collectively (TTB). The optimum BW/TG ratios for SP and DP were 0.296 and 0.866 for TT-1, 0.376 and 1.156 for T...
The repeatability of seminal characteristics of stallions. Fifteen seminal characteristics were measured in ejaculates from 4 laboratory stallions and from 164 commercial stud stallions. Complete field and laboratory data were available from 536 and 531 ejaculates, respectively. These were obtained over 4 breeding seasons (1974/75-1977/78) and 9 breeds were represented. Stallions at commercial studs produced 1-13 ejaculates at intervals of approximately 4 weeks and ranging from 1 h to 1 year apart. Intra-class correlations or 'repeatability' of each seminal characteristic were calculated. Significant between-stallion variation occurred in all characte...
Observations on the potential role of oesophageal radiography in the horse. Radiological features of the oesophagus of 7 normal horses and 13 with oesophageal lesions are described. The use of barium sulphate as a contrast agent and the techniqes of its administration are discussed. It is suggested that chronic intermittent oesophageal impaction with food material was a predisposing factor in the development of a localised oesophageal dilation in 3 horses and that one other probably resulted from an injury. A similar dilatation was seen which resulted from oesophageal constriction by a vascular ring. Megaoesophagus was seen in 2 ponies associated with grass sickness a...
Application of a chemically inactivated, adjuvanted vaccine to control abortigenic infection of mares by equine herpesvirus I. A chemically inactivated, adjuvanted vaccine prepared from a virulent strain of Equine herpesvirus I (EHV-I) was used to immunize pregnant Thoroughbred broodmares during a five-year field test designed to determine its safety and efficacy. Each mare in the vaccinated groups received 3 intramuscular injections of vaccine beginning immediately prior to and during the last half of pregnancy. Vaccine was injected at approximately 60-day intervals. The accumulated incidence of EHV-I abortions among vaccinated mares during the field trial period was 1.6/1000 as compared with an incidence of 6.8/1000...
Radioimmunoassay and in-vitro bioassay of serum LH throughout the equine oestrous cycle. Mares were bled once daily throughout a cycle, or 3 times daily from the first day of oestrus to the 2nd day after ovulation. LH was measured by heterologous radioimmunoassay and by an in-vitro bioassay based on LH-stimulated testosterone production by mouse Leydig cells. The patterns of bio- and immuno-active LH during the oestrous cycle were similar but not identical, so that in both groups of mares the ratio of biological: immunological (B:I) activity during the LH surge was significantly higher before than after ovulation (P less than 0 . 001). Considerable individual variation in cycle me...
Importance of testicular hormones in maintaining the annual pattern of LH secretion in the male horse. Serum LH was measured by radioimmunoassay in 5 long-term (greater than or equal to 3 years) castrated male horses bled at 30-min intervals for 2 h twice a month from March to February. There was no significant effect of month on LH levels; however, mean levels were significantly lower in spring than autumn (P less than 0.05). By contrast, stallions in the same environment showed a markedly seasonal pattern of LH secretion, with LH rising at the onset of the breeding season to reach levels in late spring 3-4 times those in early winter. Despite differences in seasonal patterns of secretion, ann...
Pituitary and chorionic gonadotrophic control of ovarian function during early pregnancy in equids. Concentrations of FSH, LH, chorionic gonadotrophin (CG) and progesterone were measured during early pregnancy in mares and donkeys carrying normal intraspecies and transferred extraspecies conceptuses. A secondary rise in progesterone concentrations occurred in normal intraspecies horse and donkey pregnancy soon after the appearance of CG but FSH concentrations continued to fluctuate and were not influenced by CG production. In donkeys carrying transferred horse conceptuses FSH concentrations fell sharply and progesterone concentrations rose steeply, coincidental with the appearance of abnorma...
Chlamydia psittaci induced pneumonia in a horse. An agent lethal to embryonated chicken eggs was isolated from lung tissues of a quarter horse mare with a fatal respiratory disease. The lesions induced in embryonated chicken eggs, the tinctoral properties, the ultrastructural morphology, the resistance of the organism to sodium sulfadiazine, and the presence of a chlamydial complement fixing antigen, identify this isolate as a member of the family Chlamydiaceae and suggest the agent to be Chlamydia psittaci. Two Shetland ponies experimentally infected with the isolated agent developed subclinical infection as demonstrated by an increase in c...
Effect of pregnancy and collection technique on prostaglandin F in the uterine lumen of Pony mares. Uterine flushings were obtained through the cervix (Method A) and through the wall of the uterus after hysterectomy (Method B) of ovariectomized Pony mares after s.c. injection of oestrogen for 1 week and progesterone for 2 weeks (Exp. 1). Non-pregnant and pregnant mares were flushed by Method A on Day 14 after ovulation and the flushings compared with those of non-pregnant mares injected i.v. with flunixen meglumine, a prostaglandin synthetase inhibitor, shortly before flushing (Exp. 3). Uterine flushings were also collected by Methods A and B from non-pregnant and pregnant Pony mares on Day ...
Antigenic properties of some equine influenza viruses. The antigenic relationships between the haemagglutinins of five A/equine-1 viruses and between six A/equine-2 viruses were examined using post-infection ferret and immunized pony sera. Similar results were obtained with sera from both species for the A/equine-1 viruses and these confirmed minor antigenic differences between the prototype A/Prague 1/56 virus and viruses isolated in England in 1973 and 1977. Considerable antigenic differences were found between five of the A/equine-2 viruses, using ferret sera, but these differences were less evident using pony sera. The response of ponies to th...
Control of the oestrous cycle in mares with altrenogest. The clinical effectiveness of the synthetic progestagen, altrenogest, was evaluated in field trials with 449 mares during the 1980 breeding season. An oral dose of 27 mg altrenogest was administered daily for 15 days. In the first trial treated mares were compared with controls, and in the second trial the effectiveness of treatment for prolonged or erratic spring oestrus was evaluated. Oestrus was suppressed in 94% of the treated mares in the first trial. The post-treatment response was related to the stage during the transition from winter anoestrus to the spring breeding season and degree o...
Enteritis in foals induced by rotavirus and enterotoxigenic Escherichia coli. Colostrum-deprived, colostrum-fed or suckling foals were orally inoculated with foal rotavirus and enterotoxigenic Escherichia coli derived from a calf. Neither agent given alone caused diarrhoea in foals aged 1 or 2 days, although with rotavirus, 2 of the 3 inoculated foals became depressed 3 days after inoculation and all 3 were excreting rotavirus in the faeces. Inoculation of both agents induced diarrhoea in colostrum-deprived, colostrum-fed or suckling foals aged up to 16 days. There was an apparent age-related resistance to diarrhoea which developed between 2 and 3 weeks of age. It was r...
Tendon fibromas in 2 horses. FIBROMAS arise from connective tissue and occur in all domestic animals (Smith, Jones and Hunt 1972; Stannard and Pulley 1978). They are most frequently noted in the dermis or subcutis, but may be present wherever connective tissue occurs. In the dermis and subcutis of the horse fibromas are grossly similar to sarcoids and may be difficult to differentiate (Baker and Leyland 1975). Fibromas have been described as tumours of the tendon sheath or tendon proper in man (Flynn 1975), but have not been described in this location in the horse.
Transmission electron microscopy of horse embryos 3-16 days after ovulation. The 23 embryos were obtained by flushing the reproductive tract. Though the general cytology was observed, most attention was given to the formation of the embryonic capsule. It first appeared as a thin uniform layer on the inner surface of the zona pellucida of embryos recovered from the uterus on Day 6. By Day 8 the capsule was about 1 micron thick and the zona pellucida had been shed. In fixed embryos of 11 days and over the capsule was 3 microns thick and had a finely stippled but otherwise homogeneous appearance.
Effect of prolonged administration of anabolic and androgenic steroids on reproductive function in the mare. Administration to mares of the anabolic steroid, methandriol, at the maximum recommended dose (300 mg every 3 weeks) for 1 1/2 years had no effect on reproductive characteristics except for suppression of GnRH-induced LH release and a tendency to suppress basal LH levels and the height of the ovulatory LH surge. A 4-fold increase in dosage caused marked suppression of basal LH, the LH surge, and GnRH-induced LH release. Other reproductive responses were minimally affected. There were no behavioural effects, and no changes in weight occurred when mares were compared with matched controls. Small...
Effect of PGF-2 alpha on LH receptors in the equine corpus luteum. As quantified by Scatchard analysis, a 27 000 g crude luteal membrane fraction contained a single population of unoccupied LH receptors characterized by high affinity, ka = 0.647 +/- 0.158 X 10(11) M-1 and low binding capacity, Rt = 4.91 +/- 0.78 X 10(-11) M/mg membrane fraction. Acceptable hormonal specificity, reversibility, saturability, high affinity and tissue specificity indicated that the binding protein was a physiological receptor. To ensure that the methods used for Scatchard analysis were valid, hCG was characterized for specific activity and maximum bindability, non-specific bindin...
A quantitative study of the histological morphology of the endometrium of normal and barren mares. The density of uterine glands, height of surface epithelium, numbers of hemosiderin laden macrophages, inflammatory cells and layers of periglandular fibrosis were evaluated in uterine biopsies from 40 mares. These features were found to be highly variable in normal equine endometrium. Minor pathological changes appeared to be masked by this normal variability. Atrophy of uterine glands was recognized in mares which had been barren for more than three years. No significant differences were found between barren and normal mares in the height of epithelium, number of hemosiderin laden macrophage...
Genetics of Standardbred stallion reproductive performance. Reproductive performance of 10 Standardbred stallions was related to the probability that the embryo resulting from a given mating would be heterozygous for transferrin or plasma esterase. Fertility, measured by foaling rate per insemination or by foaling rate per year, showed a highly significant regression on the probability of offspring heterozygosity for transferrin and, to lesser extent, for esterase. Substantial differences between stallions in the slope of the regression line and no deficiency of foals homozygous for either protein suggests that the relationship to fertility is indirect...
Identification of stage-specific and hormonally induced polypeptides in the uterine protein secretions of the mare during the oestrous cycle and pregnancy. Uterine secretions were obtained on Days 4, 8, 12, 14, 16, 18 and 20 of the oestrous cycle and early pregnancy. Acid phosphatase activity was significantly affected by day of the cycle, reaching a maximum at days 12-14 during the luteal phase and then declining to almost undetectable levels, by Day 20. In pregnant animals, activity continued to increase beyond Day 14. Two-dimensional polyacrylamide gel electrophoresis showed that albumin was a major component. However, a number of unique proteins of non-serum origin appeared in mid-cycle but had disappeared by Day 20. One of these was a basic ...
Ovarian follicular populations in pony and saddle-type mares. Five pony and 5 saddle-type mares were used to compare total ovarian follicular populations between breeds. The animals were hemi-ovariectomized at the preovulatory stage during the breeding season and the ovary bearing the large preovulatory follicle was studied using histological techniques. Pony and saddle-type mares did not differ as to mean number of primordial follicles, mean number of growing follicles, the variability of these numbers and follicular distribution into various size classes. No difference was detected either in the initiation processes of follicular growth, oocyte growth,...
Anthelmintic efficacy of ivermectin given intramuscularly in horses. The anthelmintic activity of ivermectin was evaluated in 18 female horses with naturally acquired parasitic infections. Horses were treated once (IM) with vehicle only (n = 6), 200 microgram/kg of body weight (n = 6), and 300 microgram/kg (n = 6). Efficacy of both dosages of ivermectin was greater than 99% against Gasterophilus spp, 100% against Trichostrongylus axei, Habronema muscae, H majus, and Draschia megastoma, 98% to 99% against adult cyathostomes, 86% to 97% against 4th-stage cyathostomes, and 100% against adult large strongyles. Although ivermectin was incomplete in its activity agai...
Effects of adenosine and deoxyadenosine on PHA-stimulation of lymphocytes of man, horse and pig. 1. Adenosine inhibits thymidine and uridine incorporation of PHA-stimulated lymphocytes of man and horse at concentrations higher than 50 and 10 microM, respectively. Deoxyadenosine is inhibitory at concentrations higher than 100 microM. Thymidine and uridine incorporation of porcine lymphocytes are elevated 5-7-fold by 25-100 microM adenosine, deoxyadenosine, inosine and hypoxanthine. Leucine incorporation of PHA-stimulated lymphocytes was affected by adenosine and deoxyadenosine in the same way, but to a lower extent. 2. Effects of adenosine and deoxyadenosine were more pronounced at shorter...
